Conceptually, a computing system (e.g., a computing device, a personal computer, a laptop, a Smartphone, a mobile phone) can accept information (content or data) and manipulate it to obtain or determine a result based on a sequence of instructions (or a computer program), effectively describing how to process the information. Typically, the information is stored in a computer readable medium in a binary form. More complex computing systems can store content including the computer program itself. A computer program may be invariable and/or built into, for example, a computer (or computing) device as logic circuitry provided on microprocessors or computer chips. Today, general purpose computers can have both kinds of programming. Storing content (or information retention) is of one the core functions of computing devices. Today, numerous types of computing devices are available. These computing devices range widely with respect to size, cost, amount of storage, and processing power. The computing devices that are available today include: expensive and powerful servers, relatively cheaper personal computers (PC's) and laptops, and less expensive microprocessors (or computer chips) provided in storage devices, automobiles, and household electronic appliances.
Today, the Internet is widely used for various applications and the general public by and large is familiar with accessing content via the Internet, especially from numerous commercial and public web sites that have become available over the years. Typically, a web browser (e.g., Internet Explorer, Mozilla Firefox) is used to interact with the Internet. A web browser can, for example, be provided as a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource (e.g., a web site) can be identified by a Uniform Resource Identifier (URI). An information resource can, for example, include images, video, text and other forms of content. Hyperlinks can be present in a resource and can enable users to easily navigate their browsers to related resources.
HyperText Markup Language (HTML) is the predominant markup language for web pages. HTML can be used to create structured documents by denoting structural semantics for text (e.g., headings, paragraphs, lists) as well as for links, quotes, and other items. HTML also allows images and objects to be embedded and used to create interactive forms. Typically, a web page is written in the form of HTML elements consisting of “tags” surrounded by angle brackets within the web page content.
Original web browsers were static in nature, designed to only render hyperlinked documents in a relatively straightforward manner. Later, scripting protocols such as JavaScript were developed, which, among other things, allowed scripts to be embedded in a resource in order to provide simpler dynamic functionality to support user interactions and animated menus.
AJAX, which is an acronym for Asynchronous JavaScript and Extensible Markup Language (XML) can be considered as a group of interrelated web development techniques used on a client-side to create interactive web applications. It is generally believed that the use of AJAX techniques has led to a dramatic increase in interactive or dynamic interfaces on web pages. Today, AJAX applications can rival desktop applications when it comes to speed and performance.
Today, processing a webpage with executable code (e.g., JavaScript) can be relatively complex and has resulted in development of relatively more complex web browsers over the years. To illustrate this complexity, FIG. 1A depicts the simplified operations of a typical web browser. Referring to FIG. 1A, a resource (e.g., a web page) is downloaded from a web server 10. Images from the web page are separated out by an image separator 12. The web page is then fed to a document object model (DOM) parser 14, which parses the web page into a DOM data structure (e.g., a DOM tree) 16. The DOM data structure 16 can represent an abstract syntax tree of the document. Content referenced by the web page is then fetched from the web server 10 and in-lined into the DOM. As the content necessary to display the page is downloaded and decompressed, the web page becomes available for viewing. Typically, the web page layout is incrementally solved and drawn to the screen. A layout module 18 performs the laying out of the elements of the web page, along with images decoded by image decoder 11. A rendering module 20 then renders the web page in the browser window.
After the initial page load, scripts (e.g., JavaScripts) 15 respond to events (e.g., events generated by user input or server messages). It should be noted that the scripts 15 can then rewrite the DOM data structure 106 based on the events. This, in turn, causes the page layout to be recomputed and redrawn.
Generally, loading an HTML page can set off a cascade of events: the HTML page is scanned, parsed and compiled into a document object model (DOM) which can be an abstract syntax tree of the document. Content referenced by URLs can be fetched and in-lined into the DOM. As the content necessary to display the page becomes available, the page layout can be incrementally solved and drawn to the screen. After the initial loading of the HTML page, scripts can respond to events generated, for example, by user input and server messages, typically modifying the DOM. This may, in turn, cause the HTML page layout to be recomputed and redrawn.
Today, Web pages/applications are typically written in HTML language. Below is a very simple HTML page as an example:
<HTML> <HEAD>  <TITLE>My first HTML document</TITLE> </HEAD> <BODY>  <P>Hello world! </BODY></HTML>
When a browser obtains this simple HTML page from a web server, it tokenizes the page first. A “lexer/tokenizer” can process the page (usually character by character) and extract its tokens. The tokens of the example above are: “<HTML>”, “<HEAD>”, “<TITLE>”, “My first HTML document”, “</TITLE>”, “</HEAD>”, “<BODY>”, “<P>”, “Hello world!”, “</BODY>”, and “</HTML>”. A parser can use these tokens to construct a DOM tree and to checks the validity of the document, for example, by using push-down automaton as is generally known in the art. To elaborate even further, the structure of the DOM-tree for the exemplary HTML page is provided in FIG. 1B.
Popularity of web pages and more generally documents that include executable and non-executable content are evidenced by their ever increasing use in everyday life. Accordingly, improved techniques for processing or presenting them would be highly useful.